缩尺效应对粗粒料压实密度影响的试验研究

堆石料的级配缩尺后的试验替代料与原级配料的试验结果之间存在一定的差异,弄清这种差异对准确把握原级配堆石料的力学性质十分重要。将缩尺效应归结为最大粒径和级配结构两部分变化产生的影响。利用土的连续级配方程结合相似级配法缩尺的思路,设计了大量最大粒径分别为20,40和60 mm的试验级配。对各级配粗粒料进行了表面振动压实试验,研究了最大粒径和级配结构对粗粒料压实密度的影响。最大粒径和级配结构对粗粒料压实密度的影响可以用一定的函数形式定量表述,建立了考虑缩尺效应的粗粒料压实密度的预测模型,探讨了该模型对不同性质粗粒料的适用性,并用多组室内最大干密度试验数据进行了验证。此外,提出了一种能够定量研究粗粒料缩尺效应的思路。

Experimental study on effect of scaling on compact density of coarse-grained soils

There is a certain difference in compact density of rockfill materials between the real gradation and corresponding scaling gradation. In order to describe the difference quantitatively, the scaling effect can be divided into two parts, changes of the maximum particle size and the gradation structure. With the mentality that the continuous gradation is combined with the similar gradation method, many gradations of rockfill materials are designed, and their maximum particle sizes are 60, 40, 20 mm. The surface vibration compaction tests are conducted to study the effects of the maximum particle size and gradation structure on the compact density of rockfill materials respectively. The effects of the maximum particle size and gradation structure on the compact density can be described quantitatively by using the proposed function form. The prediction model for the compact density of rockfill materials is proposed, which considers the effects of the maximum particle size and gradation structure, the applicability of different rockfill materials is discussed, and the accuracy of this model is verified through a number of laboratory compaction test data. In addition, a way for quantitatively studying the scaling effect of rockfill materials is proposed.